General intelligence varies among primates of same species

Washington, June 17 (ANI): In a study on the cotton-top tamarin, an Indian-origin scientist at Harvard University has for the first time shown that intelligence varies among monkeys within a species.

Led by Konika Banerjee, a research assistant in the Department of Psychology at Harvard University, the researchers tested for broad cognitive ability by identifying high, middle, and low performing monkeys, determined by a general intelligence score.

General intelligence, or “g,” is a hallmark of human cognition, often described as similar to IQ and its effect in primates may offer insight into the evolution of human general intelligence.

The study is the first to examine the differences of broad cognitive ability in primates within a single species.

“We found that there was substantial individual variation in performance on these tasks. A significant proportion of that variation can actually be accounted for by something that looks very similar to the general intelligence, or ‘g’ factor, in humans. It appears to be the case that tamarins have something very similar to our general intelligence,” said Banerjee.

General intelligence, or “g,” refers to the positive correlation of an individual’s performance on various subtasks within an intelligence test.

The researchers found that “g” accounted for 20 percent of the monkeys’ performance on the tasks in the study, while the remaining 80 percent of the variation in performance was due to task-specific or environmental circumstances in testing the monkeys.

Human “g” accounts for 40 to 60 percent of the variation in an individual’s performance on the various subtasks of an IQ test.

Thus, the researchers proposed that an increase in the magnitude of “g” was integral to the evolution of the human brain.

“General intelligence is an important component of human intelligence, but it is also possible that it relies upon ancient neural substrates. If different primate taxa differ in the magnitude of ‘g,’ with humans standing out from the rest of the pack, this might help explain how we, uniquely, can combine thoughts from different domains of knowledge to create new representations of the world. This cognitive domain general ability, captured by ‘g,’ is something that you might see to varying degrees in other primate taxa,” said Banerjee.

This study was conducted among 22 cotton-top tamarins, who were administered 11 unique tasks designed to assess different cognitive functions including working memory, executive control, information processing speed, and inhibitory control.

The researchers found that monkeys with higher “g” scores tended to outperform monkeys with lower scores across the various subtasks in the cognitive task battery.